2.5 hp HF friction drive.

cannonball2 said:
You must be really lifting the motor to get that much of a change. My Lifan raises less than a 1/2" to disengage. I bought a HF engine. I am sure it is a good engine from what I have read here on the forum, but the quality of the external parts is way inferior to the Lifan. The Lifan looks more along the quality of a Honda. None the less am looking foward to another build using the HF engine, friction drive of course!
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I think you are right about the quality of the exterior parts and even the design for our purpose. the muffler exhausted right under the seat until I moved it. The gas tank leaks at the mounting points. This isn't anything but poor quality control. I had to remove the muffler cover so I got myself a nasty burn on my knee. When I get the new rear wheel on (hopefully today) I am going to most likely have to wear long pants to ride the thing. Not much of a sacrifice though.

I'm still saving my pennies I might go with that new engine that you are using. Only problem is I swore this was my retirement bike. No more builds and ride this as long as I was able to ride.

I wish I had built one with a scooter rear wheel drive though. This is a huge motor for that but it would be eminently doable.
 
The 24" wheel was due in today so I did some work on the bike to get it ready. In the process I found that the governor shaft moved up and down in the motor doing god only knows what. I removed the cotter key and blocked the shaft all the way out so it won't get in the way. The motor seemed to run better of course that is probably my imagination.

The wheel came in and I was ready. I had the tire and tube ready for it so a little duct tape on the spoke ends and put it all together. It even fit and the motor is more level than it has ever been before. I welded some extensions onto the two kick stands. It's ready to test, if it ever stops raining. I did pedal it in the sprinkles and it does pretty good just that way. I will have to kick it over to see how it does on ride baby ride.

The 24" rear wheel doesn't seem to make it any harder to get onto the bike. The muffler will be cold when I get on. I might drop the motor onto the tire when I climb off to increase the distance between my old leg and the hot muffler. Might not help but it couldn't hoit. I actually might warm the motor up a little then shut it down drop it on the wheel climb on then lift it. I can easily drag start this one.
 
I have had to relocate the gas tank and the muffler. The muffler because it was in the wrong place. The gas tank because it was defective so I used a different tank. I had to build a heat shield tonight. I used a piece of roof flashing I had left from my camera building days. Long story. Anyway the muffler I moved to save my butt. It blue on the plastic weed eater gas tank so I put a deflector on the tank. so let's see how that does.

I did ride it a mile with the new tire and wheel. It does very well. Easier to get off with the motor lowered so I think I might try the motor lowered to get on it. Then I would have to drag start it but that has worked before so I shouldn't have too much trouble with it.
 
I was looking at my HF engine tonight, and think it easier to cut the flange off the muffler and weld a Briggs universal canister muffler to the flange. It would the exit straight out over the tire, or turn it 90 degrees to exit to the back. A quick and simple fix. Am working out the details to use a modded Maxtorque clutch. Now I have to figure what kind of bike to use. Thinking cruiser.
 
I think cruiser is always better for friction. I have a cruiser rear wheel on a mountain bike frame. Too many things on the handlebars with a mountain bike. I don't want to shift gears on a bike with that much power. I think cruiser brakes are more efficient than pull brakes. I could be wrong.

The cruiser tire is better I know for a friction roller. I am testing my new wheel and tire with no spring tension at all. It runs just fine but I'm going to put a little tension on it to make it run even better.

The muffler thing would be a good idea. I just don't weld good enough. The fix I have if it doesn't blow the bike up should work okay. Of course I do have a rather large burn on my leg from a millisecond of bad balance getting off the hot bike.

But I really do like this bike. I'm getting to the point now that I'm just doing things because I think they would make the bike a little bit better, convenience wise.
 
Well the engine crapped out on me today. Here is what happened if anyone has an idea I'm open to suggestions I don't have a clue. Bike start and acts normally. I going down a long hill I'm off the throttle. Suddenly the bike sounds like something scrapping the spokes but its coming from inside the engine. and the engine stops running completely. When I try to start it the things does the clicking sound and have very low compression. I got it home and took out the piston. it is running free, but the plug is dry so I can't tell if it isn't getting any gas is the problem. Frankly I haven't had to pull it more than once until now so I can't tell if it had better compression before or not.

So here is the plan. tomorrow I'm going to pour some gas in the plug hole and see if it tries to start. It might be that darn fuel problem again. It doesn't explain the grinding sound though. It turns over fine just doesn't start. I took it off the bike and went back to an e bike. Get a little exercise while I am working on the HF engine. I have made so many modifications, I'm petty much stuck with it even if it is defective.
 
Did you check for spark? Anything foerign stuck to the flywheel magnets. My HF engine has very little initial compression, must have an efficient compression release. That is probably why you can roll start it. Mine is actually easier to pull thriugh than my 31cc HS 4stroke. You probably have a fuel or spark issue. The Chinese spark plugs are generally known to be junk, you did change it?
 
Good to know about those issues. Yes I got a new plug last week. Something in the flywheel fins make a lot of sense that would be the sound exactly. The compression release also makes sense. the plug was absolutely dry. I think it might be a fuel thing but it is a heck of a coincidence the noise and then dying of the engine.

If the engine started right away, you wouldn't notice the slight click that is just a mechanical noise that is ther now. Since I have it off the bike now, I am going to give it a couple of thorough tests before I do anything with it again. I'll let you know what I find.
 
Did you check compression with your finger, valve lash and pushrods for straightness before dissasembly?

Sounds like you overspeeded the engine on that downhill, and prolly bent a pushrod. that would account for the clicking noise and dry plug.

Are there any fresh marks on top the piston? If so, prolly bent a valve. If the heas is off, check valves for seal by pouring some fuel in the ports and see if it quickly leaks thru.
 
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Deacon the first HF 2.5 I had made a noise like you are describing. It was caused by the recoil start mechanism hanging up. I took it apart and couldn't fix it so I returned it for a new one.
 
I couldn't get this one to fire again. It had spark and I poured gas down the plug hole and it just felt like it had no compression so I returned it. To be honest it's more motor than I was comfortable with anyway. I think I want to build a wheel on wheel drive instead of direct friction drive. I might take a look at some of the pocket kike motors, or maybe a ryobi again. I liked those a lot but didn't know how to rig them. This might be better than anything I tried before. I don't know yet.

I couldn't get it over it dying at the same time and then feeling like it had less compression. They were pretty nice about taking it back at the store. It took half and hour and some serious refusals to drive twenty miles back again the next day before they figured out how to do it, but they did.
 
I rode the ebike with a lot of assist needed and I enjoyed it how that will play out is hard to say
but I admit there was something nice about never having to pedal it.
 
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